1. Field of the Invention
The disclosure herein relates generally to the field of oil and gas production. More specifically, the present disclosure relates to a device for communicating within a subterranean wellbore. Yet more specifically, the present disclosure concerns a communication device that is deployable on a line or tubing and communicates with a downhole tool.
2. Description of Related Art
Well logging tools, used to interrogate a subterranean formation adjacent a wellbore, are typically disposed within a wellbore on a line. As these tools are drawn up the wellbore, devices within the logging tools scan, or interrogate, the surrounding formation and record data based on their scan. The data can either be recorded onboard the logging tool or transmitted up the line to the surface. The line, or conveyance member, typically comprises a wireline; other conveyance means are also typically used, such as an armored cable, slickline, tubing, and coiled tubing.
FIG. 1 provides one example of a logging operation. A surface truck 12 is used for controlling the lowering and raising of a logging tool 20 within the wellbore 5. The logging tool 20 is shown adjacent a formation 7 and conducting logging operations to obtain information regarding the formation. The raising lowering means 14 shows an armored cable extending from a spool on the surface truck 12. The wireline is strung through a wellhead 18 across a derrick 16. Logging tools known in the art can provide many different types of measurements of the properties of the formation 7. These measurements include electrical resistivity, natural gamma-ray radiation intensity, bulk density, hydrogen nucleus concentration and acoustic travel time. Logging tools can also provide information with regard to a casing disposed in a wellbore 5 and the bond between the casing and the surrounding formation. Other logging tools, referred to herein as imaging tools, tale sequential measurements along the wellbore at axial and radial spacings at very discrete measurements.
As noted above, the data recorded by the logging tool can either be recorded on the tool or transferred uphole. Often the data is digitized at some point prior to it being analyzed in order to obtain information regarding the formation 7. In some instances, the data is transmitted via means other than a wireline, i.e., such as telemetry. Double headed arrow 22 represents the general transfer of data between the logging tool 20 and the surface. Due to the large amount of data recorded by logging tools 20, problems exist in transferring this data. Often times, the required signal data transmission rates exceed the signal carrying capability of the line attached to a logging tool 20. This is especially true when dealing with imaging tools. Other forms of transmitting data uphole from a logging tool exist. These include mud pulse telemetry as well as other seismic ways of transmitting data.